floor is rusted in new project. what to do?

hey everyone. I just got a new project but i just realized the front of the floor boards completely rusted out.  the rust starts where the floor meets the firewall and goes back about 5 inches. what am i looking at cash wise to fix this? And is it worth it? the rest of truck is solid and the bag job is excellent. thanks for any help.

wat type of truck is it..... some trucks patch panels can be bought relatively inexpensive, if no one makes patch panels then you can make your own

I suppose what kind of truck it is, is fairly important. lol. its a 91 mazda b2600i. they dont make any patch panels that i could find but i also dont have access to a welder so its something I cant tackle myself anyways.

you could always get some non rusted floor pans from the junk yard and overlap and panel bond/rivet them. 

I was just reading up on that and i think thats what i will do. thanks for the advice everyone.