Biggest bang for the buck in retipping a new Denton DL103R

SoundSmith will fit your DL 103 R with a ruby cantilever and fineline stylus for less than that. 
An other Denon retipper is a guy with the nick Needlestein. Google it. I am actually listening to one of his DL 103 retips right now. It will take your DL 103 to a wholly new level. 

By the time you spend questionanle dollars on retipping or rebuilding a DL103R (arguably the best would be Soundsmith for a complete makeover with a Boron cant and line contact stylus), you would be better off with an AT OC9XML. The 103R is older than my children and isn’t up to the level of what the OC9 can deliver.

If the price of the OC9XML is above your budget, the OC9XEL will still beat a 103R but with a slightly sweeter treble than the OC9XML or 103R and much more details and musicality than the 103R.

The Soundsmith ruby cantilever with a line contact stylus is a significant improvement over a stock 103R.  That said, you’re stuck with a 103R at the same price as a superior AT OC9XEL that has zero hours on the suspension.

My budget is around $1K. I am willing to go higher if it means dramatic improvement. I want to be well below the point of diminishing return.

My budget is around $1K. I am willing to go higher if it means dramatic improvement. I want to be well below the point of diminishing return.

Andy Kim, Soundsmith, VAS, Anamighty Sound, etc. all can do excellent work on a 103...all for less than $1k. Imho if you spend more, as suggested above, other carts are more sophisticated. One noteworthy exception in the Sculpture A cart line manufactured by the wonderful Anamighty Sound in Paris. They take the magnets and a few other bits from a 103R and create a serious next level cart out of it.
What loading options and gain do you have in your diy phono?