If you want to let me know which dealer you found it at I can tell you whether they have a new 2800 in stock - if it needs any adjustments right off the bat then it must be used as a new one would be ready to sew.
You'll definitely want it adjusted properly before purchasing. Have the mechanic re-thread the machine, insert a new needle, check tensions and timing. It should be reversing properly.
It sounds like you have the parts to use the machine with or without the binding attachment.
Most of our machines will use Singer 111 presser feet but not the 2800.
Thanks,
Ron