4:2:0 is not better than 4:1:1, they are just throwing away information a different way, so if you convert 4:2:2 to either they results would look close. The problem is when you convert to 4:1:1 then convert to 4:2:0, you take a double hit.
If you graded your show at DV 4:1:1 I would not recommend you going up to a 4:2:2 timeline just for the sake of doing so, you are not gain anything, but you have up-converted and then grade (which is smart) so to do back to DVCAM would lose the benefit you gained with the method of grading you paid for.
All this depends on how much quality you want to retain. You may want to find someone that has a true Cinemacraft encoding system or another highend encoding.
To save money I would probably have the DBeta digitized to SD 10 Bit ProRes if you are using FCP 6xx, go 10 bit Uncompressed if you are still on FCP 5xx. You should be able to fine someone to do the digitizing for $75-150/hr. Then you could do the encoding with Compressor or BitVice.