Actually, that isn't completely true.
+ Router Server - cost is workstation, software, and training. You need to buy the RS software. $120,000 (Merit's price) is a lot of money to collect for an IXP project in places like Kenya, Sri Lanka, Uganda, Philippines, etc.).
If you want to get the fully supported Merit does everything version, then sure, it is going to cost some money. Mind you that price tag also includes 24x7 NOC coverage and helping peers out with their policies, etc. The service you get is worth the price. If you want a cheap Route Server, download the code (free) and install it on a cheap PC running FreeBSD or something (close to free). This can support many many peers just fine.
+ Router Reflector - cost is a router (or a unix box with gated) and training. (3620 works fine for a IXP with +60 ISPs).
About the same price as a cheap Route Server. Folks often prefer using routers over a unix box "Route Server" because the interface is familiar. So, it is understandable why this is a common choice, however, once you spend the time getting the hang of RSd, there is a lot you can do... Just my thoughts.... -abha ;)