If you're wanting decent gear you may be much better advised to buy high quality second hand, rather than going for cheap and new.
Bargains are out there for persistent and patient people; I've spent maybe £500 recently rebuilding my test and repair lab after a two decade or so absence from the field (aside from minor projects), and for my outlay I've acquired a Fluke 8840A with ac-09 option (5.5 digit, 0.005% basic accuracy, £90 inc shipping), a fully optioned Tek TDS420A scope with 7 high quality probes (£100 shipped), a Black Star Jupiter sig gen (only 2MHz, but I used one in the 90s and like it, £45 shipped), a TTi 1906 (5.5 digit programmable DMM, 0.05% basic accuracy, £63 shipped), several other meters, a couple of logic analysers, and a couple of power supplies.
Just got the Fluke back from the calibrators (free, I admit I got extra lucky there) and it hit 0.003% on the 2-20v dc range. No brand new Chinese gear is going to get anywhere close to that for less than several thousand quid.
There's no substitute for quality, and that's where your sig gen price difference comes from. You're paying for better quality components and better design which equate to longer service life and better output signal quality.