A Howa dose what it says on the tin & the same as any other rifle from a CZ to a bespoke H&H it will only ever be as good as the user, but will hit what ou point it at but £500 is too much secondhand unless it has extras of is modded in some way I'd buy new for the difference and know its ok and how many rounds it's had through it.
The strength and part of the confusion surrounding Howa is the range of models.
If the 243 on offer is a blue version with the standard Hogue stock and has no other 'juicy bits' - eg good mounts, mod etc, then £500 would get you a brand new one with a little shopping around. If its a stainless version with a B & C stock, its a very good buy - and so on etc etc. This makes it quite hard to judge values at times.
Whilst not loving the basic Hogue stock, it does perform - despite forestock flex. The Framed Hogue is different and the B & C totally changes the rifle. Stock changes are a near mix and match/ drop it in situation - so the option to change at a later date remains. Current UK stock holdings are based upon actions and stocks coming together at the order stage - so, recent B & C s/a delivery delay aside, most of the 'parts' are on the shelf and ready.
Every Howa we've come across shoots well, not a lemon yet.
The plastic Mag conversion is a great idea and Ok design in just plain the wrong material - needs a metal floor frame and a better latch design for field use. The Sonic mod doesnt float my boat either, I'm a Harris preferee as well. So the Combination package - whilst on paper a good deal, doesnt do a great lot for me personally. I'd rather spend on the higher level stocks.
Secondhand, as Apache points out there will be an economic consideration. Prices are low ( ish ) and some dealers are already under-cutting. So residual values are going to be fraught. But those that do come up tend to be offered at not much below new price - because there simply is nowhere really to go price wise. Swapping and changing kit is ( I suspect! ) 90% of the joy of this hobby of ours . That to me is the biggest potential downside to Howa choice. But every one we've sold is still in its original happy home!