Upload & Sell: Off
On 5D, for $500, I'd buy
1. Zuiko 24mm 2.8 for under $140 (Not easiest lens to find for under $150 but still possible)
2. Zuiko 35-70mm 3.6 for about $100 (You will need to wait a bit but often sold under $100)
3. Contax 80-200mm for around $260 (BGN/E grade lens on KEH goes around $250 from my memory)
+ Adapters for around $10 each for cheap ones = Aprox $530
I only used 35-70 3.6 from these and it was lovely. All these 3 lenses seem to be very well regarded on many photographic forums and despite being bit slow, It would make compact and excellent landscape package on budget I think. Adding in cheap 50mm would make this one of best all-around alt package on budget perhaps?
This would be what I would buy if I had $500 right now.
But if I had to start from scratch including the cam, I'd pick
Sony NEX 3 for around $200 and couple of Minolta lenses like 50mm 1.4 and 35-70mm 3.5 and/or couple of Canon FD lenses with adapter. This way, You can get plenty of alt lenses/fun for under $500 with this route I believe.
Speaking or alts, Did anyone else noticed that prices on many Alt lenses going up like no tommorow?
We could bought Zeiss 50mm 1.7 for like $120 year or 2 ago, but they are going for like $200+ these days. Which you could get Zeiss 50mm 1.4 for same $ year or 2 ago. Same story with many other Zeiss and Zuiko and other alt lenses.
I might be wrong, but that is what I saw from Ebay, KEH, Adorama, BH and classified these days.