Do it at your own risk.
Upconversion is a process of resizing and sometimes changing the frame rate of source SD footage in order to make it playable in HD.
Shooting Digital Betacam is certainly cheaper than shooting HD. But you get what you pay for. Upconversions can sometimes full a casual observer but when placed next to footage shot natively in HD the difference will be obvious. There are times when you must upconvert archival elements that exist only in SD. At other times specialty SD cameras such as “helmet-cams” may be necessary. Networks typically have a provision for this but they frown at upconversions done to save production costs.
If you decide to shoot SD 100% finish your show in SD and only upconvert the final color corrected master. If your budget allows do the titling in HD for much crisper graphics.
Examine your spec sheet first to understand the allowed percentage of upconverted material in a finished show. When booking an upconversion explain to the facility representative what type of material you’re upconverting so they can recommend the best process.