I think the main difference between cheap and not so cheap ballpoints is the weight, and materials used, rather than the refill.
A plastic pen is always going to feel lightweight and cheap, but then some writers want that, plus, pens are easily lost.
A heavier pen feels more substantial and might even write a slightly heavier line on paper, but also it's worth noting that metal pens tend to get 'top heavy', especially if the cap is posted on the top end of the pen body, more in rollerball than ballpoint.
I bought a small-ish ballpoint last year which is probably the best I've tried, the Franklin Covey Freemont, it's just right (for me) in weight, width, grip and look.
It appears the pen is made by Cross with the lifetime guarantee. The refill is the normal Cross/F.C. version, which does limit choices of ink colours.
Try Monteverdi's site for a wide choice of refills that don't seem to appear in the high street shops.
It's almost worth starting with which refills you like, then searching for the pen you like, that takes that refill.
The common types are 'Parker type' and 'Cross type' refills, but the far east manufacturers tend to use their own types, which are not Parker or Cross fit.
If you can find them, you might want to try the PaperMate Inkjoy Gel pens which are said to be super smooth writers.
( I would like to try them myself, but not seen to date in the UK....still looking.)
(Regarding the Pilot Acroball, a really smooth and value for money pen, good finger grip too, I bought several.)
Photo shows the F.C. Freemont (29 grammes) next to the Acroball (9g) for comparison.
Edited by Mike 59, 03 October 2016 - 10:28.