Hi!
Great to hear that some drummers are looking to record themselves! I've been playing and recording for 10+ years and on a budget you can definitely come up with something decent.
If you're looking to record for your own purposes (recording practices, etc.), two mics with a 2-channel interface is plenty.
You'll need to get yourself 2 large-diaphragm condenser mics and place them 3-6 ft in front of the kit and about waist high (there's other opinions on this though).
Having a stereo recording is much better than just having a mono room mic. I also wouldn't recommend gating the drums...don't know why you'd need to unless you're looking for an effect when mixing.
If you can afford to spend a bit more on an interface/mics, here's what I would recommend:
4 channel (4 mic preamps) M-Audio interface (don't know models)
2 SM57's (one for kick, one for snare...if you can get a Beta52 for kick, do it)
2 Large Diaphragm condensers: MXL makes inexpensive mics that will work for your budget
That would be a nice starting setup, I would think.
Here's my rig...it's a bit bigger:
Dual 1.42 GHz G4 + Dell 17" Display
Pro Tools LE
Digi 002 Console (18 ins, 18 outs)
M-Audio BX5 Monitors
4 SM57's (for snare and three toms, guitars, etc.)
1 Beta 52 (for kick)
2 Shure KSM 27s (for overheads, acoustic guitars, etc.)
1 Røde K2 Tube Condenser (for room mic, vocals, etc.)
M-Audio Octane 8-Channel ADAT Preamp - I run this via an optical cable into my Digi002...I usually run the drums into this when recording as it's a bit cleaner than the 002's 4 preamps.