As another option, if you really wanted to, you could keep the account the way it is, and make a range tank without summoning, and get to 99 range and defense while collecting charms at the same time, then you could build almost the same account. I know it's not easy to do something like that, but you could do it with enough time and effort.
If you don't want to, and want to do something productive, go get range. Definitely. I saw a great pking video of a 99 range pure with steel titan, he was doing amazing in multi combat, he could kill 3+ people if a large group rushed him, even with one defense. That would be hard to beat with 99 defense. You would be level 104+12 as a maxed range tank with summoning. You would be fighting maxed zerkers w/o turmoil (106) and mains at that level, when w/o summon. You would get into GWD teams in a heartbeat with 99 range, defense, and summoning; so money wouldn't be a problem. Ultimately, I say go for it.