I have what I consider to be a mid range 2.1 channel setup that consists of a pair of Quadral Quintus 215s floor standers running off a Rotel RB-990BX power amp and a Wharfedale SW150 10" active sub.
For a source I have an ODAC external usb dac bridged via asio4all with my internal Asus Xonar DX card as the output quality of the usb DAC is audibly better than the Asus card.
So as far as room correction goes when I say "on a budget" I'm thinking <$200 for a usb microphone and say one of the free DRC programs listed here http://thewelltemperedcomputer.com/SW/AudioTools/RoomCorrection.htm
Is there much of a benefit in going the cheap route with DRC or am I better off waiting until I have a higher tier system and the $$ so that I can afford to do this properly with a decent microphone and a software package such as Acourate?
I think you can get very good system tuning results with a calibrated mic and free software if you're patient. I personally use a combination of Holm Impulse, Room EQ Wizard (REW), and RePhase. All three are free tools with different functionality, and in combination you can get very good results.
You'll need a calibrated mic anyway for any of the more expensive DRC solutions you're thinking about, so that wouldn't be wasted money. You can get one for less than a hundred dollars if you look (PE offers one for $60, I think). Having one around can really reveal a lot of system problems that can't be discovered "by ear," so a mic is a good investment in my opinion.