I didn't know Slazenger still made clubs! I though Slazanger clubs are now under the Dunlop name. Anyway, the old Slazengers were good for better players. They had the Seve blade back in the 1980s that the newly-retired Seve Ballesteros used. I'll ta...
Recently they dropped their prices on demos. Really, you are just paying for shipping to your house and back to them. They used to have a limit of 4 demos per order, I assume that is still the case. They allow you to keep the racquet for up to a week...
There are many tennis stores that would allow you to demo racquets. Also, if you have a close friend, you can ask if you can exchange racquets for a day or two. This is how I changed my old racquet to the Babolat Pure Drive.