This will be the first of many articles about the “grey” market for Network equipment and what is the most cost effective part for a particular function. Product selection is a very important part of any budget oriented network engineer.
For Cisco there are only a few Layer 3 Gig switches worth consideration at all. You must take in a few considerations. If you absolutely require stacking, you are pretty much pidgin holed into the 3750G models. These are still quite expensive and I do not see the cost on these coming down any time soon. You can usually find a WS-C3750G-48TS in the 1500$ to 2000$ range. These have 4 SFP ports uplink and do not have the licensing “issues” that the 3750e/x (And 3560e/x) line have. With the 3750e and x lines, they come with a ‘universal’ image which uses licenses to unlock advanced features. While this is all and good on the new market, it would be next to impossible to get these upgraded after it has been resold. There is also nothing preventing cisco from refusing to issue licenses past the EoL period. For this reason, I never recommend the 3750e/x lines unless it is for Layer2 functions only, even in new deployments.
The juniper ex line has stacking like features and is always cheaper than cisco new. on the refurb market, its very hit and miss as it seems as soon as Juniper goes in, it doesn’t come out. That factor alone keeps refurb prices relatively high compared to MSRP.
If you do not need stacking - it is a whole different ball game. The 4948-10GE and 4948-S Switch lines were horrendously expensive new, and they never got a lot of love from the networking community. Due to a glut coming onto the used market and relatively little demand (due to not knowing the product line I assume), prices of these switches are quite low. The 4948-10GE has two X2 Ports (Beware - the twin-gig converters do not work in these!) and 48 Gig-e copper ports. The -S variant has 4 SFP. You can find either model for sale for around 900-1500$. This easily makes the 4948-10ge the lowest cost 10g Cisco switch out there at the moment. The one caveat with these lines is that they do ipv6 *routing* in software. I would advise anyone that is installing these to take this into consideration and to really only use ipv6 for management of these devices.
When you compare the 3560g line to the 4948, the prices are about equal. On the surface, the 3560g and 4948-s are the same switch. However, internally the 4948 has a much better buffering architecture and this makes this better suited for data center and service provider environments. This was the original intention of the 49xx line and its pretty obvious when you put these in a multi-user environment. The 3560g is roughly the same price as the 4948 - so unless the ipv6 part is killer for you - it is my recommendation that the 4948-10GE is the most cost effective refurb Layer 3 switch on the used market right now.