I agree with most of what I've seen. I personally run my 2511 to a 2507 wtih ethernet capability. Keeps me in a production environement
Then I have
1 x 2511 = 130
1 x 2522 = 300
2 x 2503 = 100 a piece
3 x 2507 = 80 - 100 a piece
2 x 2501 = 100 a piece
2 x 2912 switches = 100-150 a piece
All of my routers are 16/16 and Enterprise IOS.
The 2610 is a good replacement for the 2522. It's modular, but no need. the only other thing that a 2610 provides is a dual LAN (2 Ethernet port) capability. Again, 2514 will do the same thing. And the modular 2500s are 2524 and 2525. Another thought is a 7000 chassis for 100 bucks (shipping just sucks, but hey, one time deal), the blades you can purchase to what your next leg is in CCNP, etc.... 7000 and an ISDN Sim will leave you everything you need, except ATM.
I currently carry MCP, MCSA, MCSE, CCNA, and CCDA. Microsoft I've been doing for years and years, but my lab certainly supports CCNP studies and a hybrid production network. I'll tell you that Cisco wants you to know the IOS based swithces, but the 2900's if purchased with the right images will do everything you need, I'm running NAT, PAT, CBAC, Frame Relay, OSPF in Broadcast, NBMA, OSPF in multiple areas, Route Redistribution with RIPv1, My 2507 is a DHCP server for two remote subnets with IP Helper address assigned at gateways, I redirect and server web pages over my interfaces and overload the ISP Cable connection. and 802.1q on my switches for Trunking. you'll need tunneling later....
All of this I bought for less than 1500 bucks. 2600s are Great, the perfect switch 3550s are 3 grand, but a 2900 maxed out can do most of what you need to do.
don't get confused by DOT1q on 2500s, your switches run it and VTP, pruning, etc.....
The most important things to have are the IOS versions at 12 or greater (your tested on it). that's the reason for 16/16 MB requirements, and the interfaces that you haev available to you.
Patience is key to the buy this at $1500. the prices have stayed up a little bit since the holiday and tax time won't help much either. Good Luck ......