Yes, it is a rabbit hole you would be diving into!
But.
There is one really cheap and easy upgrade to do and that is to get the trigger worked for $60 return post.
I bought my Howa Varmint 223rem 1:12 twist 2nd hand and someone had played with the trigger. It took a steam train to pull it and the safety no longer worked. Sent it to Glen Couglan after my first 20 rounds and have been very happy with it ever since. The rifle cost me $500 but I contacted the seller about the faulty trigger and he agreed to pay the cost of the trigger job. Very decent of him indeed.
My best groups with factory ammo were still only just under 1MOA but averaged probably just over. These rounds cost me between $16-23 per 20 and I found it difficult to get steady supply of the preferred feed locally and my budget didn't allow for bulk purchasing which around here doesn't really give you any significant benefit in cost per round so I had to keep buying what ever was available when I drove past the cheapest supplier which is about 1.5hr from home.
I bought reloading gear (rcbs kit $500) and developed some basic loads that brought my average groups down to about 0.7MOA at between 30-50c per round (using the brass from previous factory ammo), depending on bullet cost. That kit has paid for itself many times over considering i now also load 7mm-08 for about a buck a pop and factory feed is more like 3 bucks each.
I then went on to the font of information that is YouTube and discovered Nathan Foster's videos (ballisticstudies.com) on bedding and stabilising synthetic stocks. I bought his products, followed his video tutorials and stabilised the fore end and fully bedded the action which cost me about $70 for all the bits and about 4-6 hours of my time to do the job. This, along with testing torque settings on the action screws and getting more fussy with reloading brought my average group closer to 1/2MOA but still shooting 0.8s & 0.7s as well. All this was shooting in my paddocks at 100m.
Then I went and bought a Boyds stock in a lefty because I realised my right eye had deteriorated more then I had thought. Didn't need to stabilise that but did install pillars and fully bed it again. Another $70 and an afternoon or so of time plus the $200 odd for the stock.
Also added detachable mag bottom plate because changing mags while I was head shooting pests at 150m was easier when I didn't have to top load. Picked it up off another forum for the bargain price of $150 plus 2x AI 10 shot 223rem mags at something like $60 a piece.
Changed my powder to BM8208 from BM2 and got even more fanatical about my reloading and my bench practice technique improved so my average groups where now between 0.4-0.3MOA.
Then I pulled the 223 barrel off (or my smith did), opened up the bolt face and put a 7mm08 barrel on, got the action trued up at the same time, along with a cheap Zastava action (which was also trued up and fitted with the Howa varmint barrel frimmed to 18.5") in a left hander because shooting pests left handed with a right handed rifle is annoying.
Now I have a right handed Howa with a 7mm08 heavy barrel in a left handed stock and a Sightron scope on it (cost me about $1400 from memory) that shoots groups of 0.3MOA quite easily at 100yds which I use for prone shooting in F-class (can keep it into about 40mm at 300yds with out too much trouble, better on a still day) and a left handed 223rem stumpy varmint barrelled Zastava that will spit 50gn bullets into sub 1/2" groups at 100yd all day long.
Oh yeah... and I'm saving for a GRS stock for my Howa that is going to be between $1000-1200.
Moral of this story is: have fun shooting your Howa while you are just getting back into it then keep it as a knock about and buy a nice Sako or something!