Confirm button to confirm, and buy now in one button

Ok. So I got Marketpress + Appointments+ installed together and working well. But, it is really confusing to users to click confirm, and then have to look for a buy now button to actually purchase it.

So....

How do I make the confirm appointment button do all these things in one:
1) Check and confirm the appointment time
2) Add the appointment to the shopping cart
3) Re-direct to the shopping cart
4) Not show a add cart or buy now button

Steps 2-4 I would think would be done all in one step by just placing the code for the buy it now button inside the confirmation function, and then re-directing. But I'm not too good with code. Please help!