The 340PD is over $600.00 now.I think like $650, and that's a good deal.
However, my good friend who owns, and shot both the R9, and 340PD said that firing the R9 is much more comfortable.
I just hope that you get good return on the 340, don't give these great guns you have away just to get an R9.
I'd sell one of your Glocks, put the money in an envelope in the safe, and add to that every chance you get.
If you give the dealer the down payment, you would have several months to get the balance up.
I just realized that I own a R9, and a 340PD, but I have shot neither.