If you are going mangroves and softies I would be tempted to run it without a skimmer. I'd try doing it with just a fuge.
The mangrove export is minimal which is why a separate fuge would be needed.
The only one I am aware of in this price range is this one, but I have no idea how good it is.
If you want a great working skimmer without the high cost, I would go with a SC aquarium skimmer. We have the SCA303. But since your tank is only 30g you could go with the SCA301 which is rated for up to 65g.
In that price range you can't beat the ASM Mini G. Isn't a flashy modern design, but works great and is powered by a modern Sicce pump. The Aqua-C Urchin in-sump model is also a good one close to your price range.
This used to be true of the SCA skimmers. I got the 302 back when it was call the SCA 150, original design. Price was like $150. Now they are $200-250 and you can get a RO, BM or Eshopps for the same price and get a better skimmer with a better pump. I was happy with my SCA 302 especially at the price it was, build quality was not perfect and the pump was cheaper, had to replace impellar twice due to the shaft breaking on one and the pinwheel coming off the magnet on another. Spent the extra $20-50 and get a skimmer wirh better parts and support. I would suggest a 110SSS or Classic 110 from RO or a BM Curve 5.
