When Borrowlenses.com first started out, there wasn't much available for Videographers (mainly photographers). It seems the line of rental equipment that can be had is expanding and includes some very cool stuff. A small 7 piece set of Zeiss Compact Prime lenses can go for upwards of $24K, or around $5K each. Not something most people want to invest in, but at least now it can be rented. Remember that you don't need to be in the area to pick the rental up, they'll box it up and ship it right out to you. You should check prices of Rental gear to see if you can
squeeze add it into the client's budget. That could save you some cash for items you don't use very often.
Also adding in to the lineup of things is a DSLR slider. One rental piece available is the consistently sold out Signature Philip Bloom Pocket Dolly - by Kessler. Boy would I love to see some Cinevate Linear tracking systems on that list too. There's also Glidecam Stabilizers, and LED Video Lights, but extremely short on the DSLR Shoulder rig lineup (sucks). Much more available at the site and the list seems to be growing every week. All found following the link.