Both are refurb'd firearms and as a result have limited colletors value.
Nevertheless, will they generally increase in value over the years as milsups, especially when supply runs out.
If you get one, try to get a rare variation and one without Ukranian (UN export stamps - seen on SVT's and T33's).
They are so cheap right now, I don't think they could be a poor investment. Look at the sksd I bought for $125 and now they sell for $300+ only a decade later. That inflation rate is only seen on other precious metals such as gold.
However, there are other more expensive pieces one could purchase that might appreciate more with age.
I have two TT's and 2 Versions of the Mosin. Will my Krieghoff, Blaser's or Luger appreciate more? Time will tell.
As with other investments, they do go up and down from time to time. Both firearms you are looking at have jumped all over the market as supply has gone up and down.