Jacket / Pants
As several have mentioned: for high value, consider used gear. Probably best source is advrider, though ebay might work well, too. It can sometimes take a while to find what you want in the right size, but there's no better value IME. If I didn't splurge on Motoport gear I intend to keep for over a decade and know with absolutely certainty will serve me well, and stumble into a cheap Aerostich Darien setup (from advrider) for somewhat better performance and ease-of-use in winter, I'd probably have Olympia gear.
Helmet
Even though your 10 yo HJC helmet fits well, I wouldn't assume a new one will fit the same. HJC used to make a model that fit my head, and its successor model(s) didn't. There are a surprising array of good helmets available at a variety of price points, especially if you have an "intermediate" or even "intermediate-oval" noggin. (Unfortunately, my loooong oval noggin is restricted to exactly
one make and model, and it isn't cheap)
Gloves
Gloves I think are the trickiest purchase. The fit can be hit or miss, quality is wildly variable among those that are reasonably priced, and my experience with leather lasting more than a year or so of nearly daily riding is dismal. While they're more expensive than some and substantially cheaper than others, I think
Motoport Racing Gloves (misnomer...I wouldn't by any stretch consider them "racing" gloves) are the best deal going. My brother has a pair that's nearly 10 years old and are in as good shape as mine of just a year or two.
Boots
I've tried a handful of different, inexpensive boots over the years. None were particularly durable or protective and they all paled in comparison to my Sidi Adventure 2s which I picked up at a great price. I would have saved money if I had just bought good boots in the first place. Keep an eye out for sales on discontinued or last-year's models.