$25K might be a tough on a SP, thinking maybe a nice 8450 Hesston for that price, you could get some really nice older Sickle Hesstons for that.  Our old 8200 would eat some damn thick hay, wouldn't do it anywhere near the speed that our Disc does.  You'd be in an 8500 for a Disc machine at that price.  Cutting 6'-8' tall Garrison the 8200 was probably under 5mph and the 9635 can do 10mph+ with minimal plugs around the squirrel cages.  Figure I can now cut and bale at he same speed which is roughly 12mph.  The turning around with a pull type kills your time, SP is almost twice as fast in the same field especially in tighter areas.  Last time we ran both together in one field it turned out it wasn't even worth bothering with the pull type.  This was 14' case SCX100 and Hesston 9635 15'.

You'd lay down 15 acres with a SP disc in no time.