I guess I wasn't clear. There is a toilet, but it just ejects into the water directly due to the lack of holding tank. But thanks for the feedback.
Well the toilet is only a small part of the expense. It will really depend on if you can find space for a stock size holding tank. Holding tanks are going to start at about $500(custom goes way up from there), vented loop at $100, Y valve at $50, hose is about $10 a foot(depending on set up, but figure at least 15 feet), macerator pump $200, deck fitting at $100 and figure at least $300 more in miscellaneous fittings and parts.
Here is a good article:
Installing a Head by Don Casey - BoatTECH - BoatUS
I don't see how you can get in a normal set up for under a grand even with your toilet, but toilets are only about $300 for a usable one. (keep in mind when yours needs to be rebuilt often easier and just as cheap to replace) You have to use quality parts, such as top of the line Trident Hose as anything else is going to stink in a few months or at least 2 years. You don't want to have to re do the hoses any time soon.
Sure you can build your own tank, and use cheaper hoses, but you will likely battle smell for a long time, then rip it all out and re do it properly.