I think the refinement system is fine as it is. Maybe enriched hammer needs to be here permanently. There's nothing wrong with allowing all players to have access to +9 gears, while the company earn some revenue in the process. +9 are hardly an end game gear by today's standards. Gods and MvPs are. +12 gears are still pretty rare and expensive, but not required by newer players by any means.
Safe 7 and enriched are pretty well thought out plan for Renewal and its Cash Shop gear. The primary issue here is not with the refinement system or Safe 7, but it's about how are any worthwhile gears for average players are from the Cash Shop, which nobody seems to protest. Most of these Cash Shop gears would not function properly without being upgraded to +9, which is probably the only reason to upgrade to be honest for most players. It's not a very sound business plan to have these player break their Cash shop gears trying to get to +9 to unlock its effect, while the company can potentially earn even more revenue by putting up the Casio of the refinement system we have today.
Also back in the early RO, you don't really need +7 gears. Getting to +4 was pretty hard already because only thing that would drop elu / ori were the MvPs. People were hunting MvP just fine on +0 gears. Now you can't even get into bio4 party without some decked out +9, especially if you're DPS classes. And situation will get even worse if you deny access to +9 gears to many players.
The price modifier was really caused by enriched hammer event, we would not see any of that if he is here to stay permanently. People will still buy HD Elu / Ori anyways for +9 to +10 upgrade.