I have to agree on this. As a GBBR I would always advise getting a TM MWS or a TM AKM, because they're so good and will work all year around, however as a first GBBR I wouldn't go that route because they're so expensive. MWS runs you about £500, then the mags are £50 each and you need a bunch of them as they're only 35rds, so you're looking at a starting investment of at least £700+. Fortunately, they need very little done to them in terms of upgrades (literally just a sixG nub in the MWS and a bavtac nub for the AKM and you'll be set), but the gun and parts will be very expensive for something you might not enjoy.
Depending on what you like, KWA do some great little GBBR SMGs which are a lot more affordable. Mags will still run you £50 each, but a KWA mp9 or mac11 will only come to about £200 new and they also perform very well out of the box. The mp7s are good too, with me hearing good things about both the Umarex and the TM ones at a price point of about £300.
Reason I talk about the TM MWS, TM AKM, KWA mp9, KWA mac11 and Umarex/TM mp7s is because I own all of them, apart from the mp7s which I plan on buying a TM one soon. All of the GBBRs I own are really great and required minimal "upgrades", so if you do want to get into GBBRs I fully endorse it as it's such a fun and far more rewarding method of playing as every hit you get will feel like 20 hits with a regular AEG. As has been said, it's not the most competitive loadout and you will be outgunned by everyone with their AEGs and their high caps, but it's so much fun and super immersive; you will get good at reloading