I'm not sure...
GF1 used is a good deal (where I am)
GF1 new isn't that great a deal from the prices I've seen mentioned here.
From the prices mentioned here for a new one, you might as well get a G3.
Do look at the EPL1 as well, if you can look past the poorer resolution LCD screen.
IMHO, the Olympus cams have better looking OOC JPEGs. The Panasonics need some PP work (ie. levels, curves, in-camera wb adjustments)
On a budget, keeping the K200 makes more sense, since you can just use the cheap MF lenses.
For the GF1, you will need to get the 14/2.5, 20/1.7 and maybe a 45/1.8 on the cheap end of things. But since you are not getting 2nd hand and on a budget its a bit of money.
Have you thought thru that the problem with your K200 maybe a lens selection and carrying issue more than an actual size/hindrance issue?
A rear panier or even a haversack hung on the handlebar may solve the issue of carrying the camera.
Just bringing one lens out (a cheap MF 24/2.8; 28/2.8 or 50/2) keeps the baggage and encumbrance small as well.
What are you riding btw? Road, MTB, TT, hybrid?
I wish I had the time to do more riding nowadays..... weekends are now just a short ride, then coffee with the blokes.