I personally fall into the camp that return pumps demand a higher priority in the total reefing budget as it ties to installation costs. Return pumps do not change if we are being honest so whatever you decide upon today chances are likely it will work for you down the road should you change things like doing an upgrade. Even though we say no, we will not upgrade, we do at some point in time. Reefs mature if we are successful. I personally feel increasing the budget gives one more room to buy quality products or products that otherwise may not be considered.
Few things to consider besides functional needs are installation, maintenance, access, and shared use. Return pump, skimmer pump, or a manifold. Buy a spare of whatever you end up using and now maintenance is silly easy because you can take any that can use the same pump offline and swap with one off the shelf. Super easy because they share the same connection fittings.
Now some here have said that the pump has been running great for X number of years. I do not doubt that. I've been there and done that, I'm busy. Well maybe lazy. Both. In any case my point is that pumps need maintenance and we should accept that. Especially to mission critical things like return pumps. New, out of the box, clean, they are moving like they should. Month one, two, three, or eighteen things start to change and the flow isn't the same. No matter how much we want to believe it deep down we know it is dirty. Film, life, micro fauna, whatever we want to call it - it is there. Example below for reference.
Note - I am not budget shaming or anti cleaning shaming just tossing out thoughts as I reply. Budget, look at what can use the same pump, connection, fittings, possibly buy a spare, and make your life easier.
Film, stombus snails, bristle worms, small crustaceans, and aiptasia on the body (not shown).