I think you need to be very specific about what you tried that did not work. How you set it up or who set it up for you. Ignitions can make or brake an engine, but, just as imprtant is the setup. Setup maybe all you need right now.
C&H invented the RC electronic ignition that brought us reliablity. BCCHI has commented on many threads here and is easily the top resident expert. He is however out of the game and I think one of the main reasons is people who do not place value on what a vendor has for sale. To me 149 $ for your DA sounds just fine. Pay it and move on.
If not I have replaced 4 ignitions in the last 10 years on various engines that were sold with crappy OE ignitions. All were hall effect sensor type and all were replaced with RCxels. With no problems so far. Most of them I bought from Hobbyking marketed as replacement units for the FTL engines they sell. These were all for 14mm plugs as that was what the engines in question used. I also stoled a RCxel 10mm unit for the Zenoah G20ei replacement from a CRRC pro that I have yet to put into service. All those units do work well.
I have a DA 50 that runs great. If its ignition dies I would probably replace it with one of Milton"s units ( I like the hall sensor bracket he has made). I believe the hall effect units are superior for starting ( this is just my opinion ).