I guess this wouldn't necessarily harm the economy in anyway. In fact, why not have them cost 50 stars from the star shop in order to keep the rarity of them. Overall though, +1.
I would really like this to be implemented. I have built many houses when the beacon block would be a nice addition to it. It would also be cool to see all the creative things people make with them! As for the buffs, i think speed strength jumpboost etc. would be fine other than the breaking haste. It would be fun in user made parkours and pvp arenas. The speed would sorta help farming i guess.. But its just the same as a 5 dollar speed pot. I don't think it would cause a lot of lag.. I mean, I don't know this but I bet you would have to place tons of em in the same place, and I bet andrew would just wrldedit that out. I thinl it would be best if the crafting for it was disabled and they were added to the nstar market. Same as the chiseled stone or the smooth double half slabs. I think baybe 5-25 nstars would be good for one beacon block. It might have an impact on the economy, but i doubt it would really cause anything negative. As long as their not craftable there probably wouldn't be many of them.
+1 Love this idea alot as long as the buff and effects are taken out. This is a very cool block would love to put it on my sky scrapers!
This would add for some nice aesthetics to building and designing. +1 if it can be added without issue.
clearing out a 200x200 section below my town for a farm would be 100x easier with haste2 though, why aren't these a thing!