i would not say anything in the $89 range has
insanely high audio quality be it pc speakers or home theater speakers. if such systems are considered good i'd love to know how higher end systems compare. typically speakers for low end systems like this are all cheap plastic enclosed boxes with speaker wire hanging out the back. the dvd player is a combo receiver/amp/dvd player which is often quite limited. i am not saying that such systems will not work (they can and do work fine in
many cases however may not be the best solution for everyone.
for reference 100gbp=150usd
anything i state as 100gbp is in pounds, anything i state as $150 is in us dollars.
z506 5.1 $99
t6300 5.1 $79
fc360 2.1 49gbp
bh6220s 5.1 279gbp
both the creative and logitech speaker choices you listed are very good in terms of sound quality for a low budget. they arent going to win any awards for performance but for that price range you shouldnt expect them too. they will fill a small room with good sound at least as good if not better than home theater systems of the same price range.
from what i could find out on the microlab set it provides some decent sound for a small budget 2.1 set. it should be comparable to the $40 2.1 sets logitech offers but definitely is alot nicer looking. its hard to call how good they will sound without hearing them in person really.
the lg looks like typical htib sets which i always avoid. they do work but you need to really watch what you are buying. as you said this is out of your budget anyways. even if you did have the budget for this set i would suggest looking for individual components instead as there are very few sets with a few notible exceptions that are any good. technically they can and do work but there are better choices out there.+
since you listed GBP i will assume you are in the UK
used complete z-5500 5.1 set on ebay uk for only 169gbp. generally this is regarded as the best set logitech made and is on par with many moderate quality home theater systems. brand new i know these retailed for $500 to $600 in the usa and it can be hard to come across them. you may be able to find them used or refurbished elsewhere so have a look around.
used z906 5.1 set on ebay uk for only 99gpb. generally this is regarded as the second best set made by logitech. this one is missing the subwoofer not sure how you feel about that. you may be able to get a subwoofer to work with the unit but i'd have to take a look at how the original subwoofer connects up to the set to know for sure.
sony floor standing speakers on ebay uk for only 56gbp. i know they usually come 2 in a box not sure about the ad as its not listed but should be for two. i gifted a pair of ss-f5000 which should be similar to my parents and they are very loud (no need for a subwoofer) but audio quality as actually suprisingly good. if you are okay with 2.0 sound you could hook this up with an amplifier or receiver and come out just a little over budget. they are tower speakers though and will take up room on the floor.
logitech x530 5.1 set on ebay uk for 49gbp brand new. i bought this exact speaker set 10 years ago for my first homebuilt computer and in fact i still have them on a spare pc. these speakers arent going to win any awards for sure but for the price they definitely offer very good performance for the dollar. its a 5.1 set for a comparable price to the microlab 2.1 set so as far as a price standpoint goes its good. i've watched movies with the set personally and while not anywhere near as good as my $1500 sound system i currently use is definitely worth every dollar i spent on it (i think it was $80-100 new when i bought it)
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if you want brand new it seems that the creative t6300 or logitech z506 would work perfectly well for what you need and are in your budget.
if you dont mind used and do not mind spending a little more the z5500 is as audiophile range as pc speakers go. they are comparable if not better in quality than $700 and under htib sets.
if you want cheap and 5.1 then the x530 which i've personally used is not a bad choice. perhaps not as good as the higher end creative or logitech sets mentioned but its a cheap 5.1 set that doesnt kill the budget.
if you dont mind looking for a subwoofer the z906 set might be worth looking into. of course i would prefer to get everything all-in-one without having to look for a subwoofer.
if 2.0 or 2.1 is okay with you and you dont mind using a receiver then the sony floorstanding speakers may be a good idea. as i said before my parents use the lower end model and they are great (at the price they were it makes me think i spent too much on my smaller speakers!) and loud enough to not need a subwoofer. you may go over budget a little getting a receiver but you can always buy more speakers in the future as time goes on to build a 5.1 set over a year or two.