I don’t recall having to pay any duty - just the list price on website delivered to the door.
I did a quick search here and found some older posts from others who have the Discovery Lpvos - initial impressions seem good but not sure of any long term usage feedback. I just threw up a thread in the optics section to try gather some feedback from other users.
Being FFP, the reticle is quite fine at 1x, although it has an illuminated horseshoe reticle so should be good for quickish acquisition. Holdovers are non-illuminated, which as Can-Down mentioned is also preferable for me - can get a bit distracting if whole reticle is illuminated..
Could pick up the discovery 1-6 lpvo and 1,000 rounds for cheaper than the primary arms lpvo.
Shooting those 1,000 rounds would be a good way to get to know your rifle, its limitations, and how an lpvo would work (or not) for you. You already have the Romeo red dot so can give that a whirl too.
After those 1,000 rounds, reassess, sell/change/keep the optic setup, and buy another 1,000 rounds!