Just looked up VA's website, looked at dates next month. Return in J is around 250,000 points plus $150 in taxes.
Note that this cost is for flying this route on VA, EY and some other partners, but not SQ. SQ has a separate, more expensive cost table.
SQ will be 175k points in Business one-way; double that for a return, add applicable (small) taxes. I can't remember if SQ fly direct to DUB, but I'll assume yes.
Of course, another option would be to transfer VA points to the SQ Krisflyer at a rate of 1.35 VA to 1 SQ, then redeem using Krisflyer's cost table. This also opens up options to redeem on the Star Alliance.
Anyway, the OP doesn't seem to be after awards but rather upgrades. Since upgrades on VA only work to Abu Dhabi (i.e. where they fly) and upgrades chant be registered on Etihad using Velocity points, as mentioned buying and upgrading on SQ would appear to be the only other option, where the upgrade requires Krisflyer miles supplied by transferring Velocity points to Krisflyer at a rate of 1.35 : 1.
I'd be fairly confident that the OP has enough points in any case to upgrade a return journey.
Note for upgrades from Economy to Business, commonly, the lowest set of Economy fares are not eligible for upgrades.