I'm late to this party but my new favourite cheap reel for kingis is a sub-$40 Okuma Revenger 55. I've tried cheaper - the Shimano IX rear-drag reels - but they kept breaking ;-) Shimano really needs to sort that out.

After seeing a little Revenger 30 take a 45 minute beating on a shark a wee while ago and giving it heaps to bust the shark off, I was impressed. Sure, the plastic spool may not be perfectly round anymore, but it handled the jandle! So my "you can't catch good fish on that POS" eclipse rods will be rocking the Revenger 55's on the next kingi hunts.

I would prefer to have stayed with Shimano reels but they don't do a good enough cheap one ;-)

I had a Saragosa 25000 but found it too heavier for all day casting.

I now use a Saragosa 14000XG, much better with weight for casting, 80lb power pro, 15kg of drag and an IPX8 waterproofness...

...couldn't help myself I had to get Swordfish Steve to add a power handle to complete the bling.

Poor man's Stella 

Rather than a penn pursuit go for penn fierce if on a budget.

I‘ve had an 8000 fierce for couple of years and is a nice little reel for money loaded with pe3 Edge braid from burnsco. Wouldn’t put it up against massive kings but handles  them up to 15kg. Fine for smaller stick baits and poppers, and would be fine for lighter to medium jigging.

Can compare against 2 other spinners I owned for quite a long time, the shimano sustain 10k and Diawa opus bull 4500, those reels were both more expensive, although opus was pretty cheap when bought it - under $150. Diawa Opus bull is still going strong and dealing to kings over 20kg sits on old blue Diawa pe 7-8 jig rod but only fish pe5 over it. Same with the sustain 10k, which use on top water rod occasionally but it did fine  on trip to white a few years ago. 

Personally prefer jigging and livebaiting for kings.

Have just bought a 20k saragosa for more line capacity and heavier work. The older models are going cheap now the new 2020 model is out. 

You also probably can’t go wrong with slammer3s from penn - very solid reels as recommended above. But again more expensive but probably better investment longer term.

Caught any big kings on it? 

Advice RE budget reel for topwater is don't, get a slammer. second hand be a good option