Following on from the previous post about building your own rack, which we found to be expensive, the second option is to rent a rack from one of the many vendors online. The third option is to build a hybrid of emulated routers and real switches, which you can read about here.
Assuming this was the route we were going to take, it's then a question of who to pick, so lets have a look at some of the vendors out there. I did a search for "CCIE rack rental" and will compare the top four. All four offer blocks of four hours.
INE - www.ine.com
INE unsurprisingly were the top of the list. Obviously they will follow their own labs, and have configured and tuned the racks accordingly.
To complete all four of their workbooks (available for $599) they recommend the following (purchased as rack tokens):
400 rack hours for the first two workbooks (1,800 tokens)
150 rack hours for workbooks 3 and 4 (650 tokens)
A total of 550 hours, or 2450 tokens.
Prices are:
100 tokens = $100
500 tokens = $500
700 tokens = $595
1000 tokens = $795
To complete all 550 hours would cost $2090
Purchasing their workbooks as well would take the total up to about $2700.
CCIErackrentals.com - http://www.ccierackrentals.com/
These guys offer a number labs to use, including CCIECert, Cisco360, INE, Narbik, IPExpert and their own. Sessions can be bought in blocks of up to 30 sessions (at 4 hours a session).
30 sessions (120h) are available for $180
Comparing the cost against the 550 hours "required" for the INE workbooks, this would cost $900
CCOnlineLabs
EDIT: They seem to have disappeared.
Proctorlabs
EDIT: ProctorLabs disappeared along with IPExpert.
Final notes
If it were me, and renting was the option I was going to use (and not saying there is a right or wrong answer here), then I think I would purchase the INE labs, and use the ccierackrentals racks. This would cost about $1400 and include everything.