In that case, you can get the Mac OS X 10.6 Snow Leopard Upgrade DVD for 29 USD and use that for a clean install* or download Lion for 29USD, but not install it and create a bootable installer of that Lion download**.
*
To create a Clean Install (formerly known as Erase & Install) of Mac OS X 10.6 Snow Leopard (the 29 USD Upgrade DVD is a fully working retail version of Mac OS X and does not need a prior installation of Mac OS X on the Mac), follow one of the following guides:
Short version: Clean Install of OS X 10.6 Snow Leopard
Long version: Mac OS X v10.6 Snow Leopard: How to Erase and Install