A typical rental fee for exotic equipment is in the 5% to 8% of retail price per day, four days rental equals a week. Meaning you might be very fairly charging $250 per day and $1000 per 7 day week for the machine. This is an industry standard for AV equipment, but I've seen it for other exotic digital electronics as well. Remember that the HT is digital transportation, in very rare supply and it is a vendor's market. Extremely expensive gear goes for lower percentages. Trucks, HDTV cameras, etc.
Of COURSE any damage, replacement parts, scratches, etc. would be additional, plus labor and shipping. I'm thinking kickstand ($77), drops that scuff the front rubber insert on the handlebar ($25), fender scratches, etc. Take pictures before the machine goes out for rental documenting its shape prior.
-iNova
http://www.glidewalk.com