I have followed closely the Master Replicas items value issue within the last year, the whole spectrum that MR offered to us. Recently many of the force fx lightsabers have started to rise within the markets, like for example Luke ROTJ, Mace AOTC/ROTS, Obi-Wan Rots and so on. People are selling many of these sabers with less than 100$ on forum, even though the true value is much higher nowadays. I see Windu fx going in ebay now with $173$ and still 3 days remaining. Some of the earlier MR products have even tripled along these years, we're talking about three figure numbers on some pieces. Like the Yoda AOTC originally cost only $249, it much more than that nowadays. Obi-Wan TPM Elite edition in high figures and so on. So definitely the values for many MR items have rised lately. I also follow like more than a dozen star wars shops that sell MR items and how people are buying these items with good percent. How do I know? Well many times I looked that there's a great MR treasure in stock and after too many second thoughts I actually fail to get it, since it's out of stock. This time for good. There is definitely a silent hunt going on and when I saw Obi-AOTC LE, I quickly grabbed it, since it was just a lucky find and it would have disappered soon. If there were coming a EFX Obi-Wan AOTC, I wouldn't mind, since I was particulary searching for the MR one. If you're planning to get the MR Vader ANH SE, which means the 1000 limited dual signature edition that our Anakin Skywalker owns, then it's gonna be extremely pricey, but truly a great treasure. Find a nice a deal and grab it if possible, since I mean it wouldn't be the same thing to own a MR Vader ANH SE as EFX Vader ANH SE. Like there's EFX Stormtrooper helmet and MR one, even though there comes changable lenses and stuff with the EFX one, it's no cooler to me anyways. I would grab anyday the MR one over the EFX, but that's just me :D. Many things affect what you choose to buy, like the hunt for certain item you have longed for, perhaps how limited it was, your own history with the certain manufacturer. Like I have many Finnish friends who lived the ICONS era as collectors and value those over the MR and so on. So it eventually comes to you, what is important to you.
add: Also, the Star Wars actors are getting older and older, like David Prowse, the man is already 73! So there's no guarantee that David Prowse would be there to sign Vader lightsaber plaques for EFX, in worst scenario the MR ANH SE was the last one we'll ever see