Just like dropping prices for PCs, genetic testing costs will constantly come down if their is marketing pressure to warrant price reductions. YSTR prices are not coming down any time soon and neither are YSNP packs or ordering individual YSNPs. However, NGS/WGS testing will continually fall.
Also, if you really want to get a little extra off these tests, there are two ways: 1) if you are testing YSTRs at FTDNA for the first time, join a FTDNA project just prior to ordering and you will get five or ten percent off; 2) you can wait for the regular sale events - next one will start in late November and end in late December. Big Y goes from $575 to $475 or even $450 (it varies for each sale). This year, YSTR upgrades went on sale for the first time. YSNP packs have never been on sale except when they are first released (first two to four weeks only).
You can be proactive or wait for others to test and then order when prices drop. I was the first under R-L226 to order the NGS test at $1,350 - now costs $775 and covers 20 % more. However, I now have eight branches of mankind from my first test and will definitely get a couple more genealogical branches over the next year or so.