Need a Purchase/Sale Agreement Drafted

[Joe P.]

I am selling a vacant land property with an installment sale in Erie County, PA.  I have a purchase/sale agreement that I use for cash sales but I need one that I can use for an installment sale.  Where can I get one or have one drafted that won't cost an arm and a leg.  Recently payed $350 for a 1 page contract review and I though that was a bit steep. I appreciate any help.  Thank you!