Aussies Travelling to Opening Day

We are headed over and on a ballpark ticking mission with Minute Maid being one that we plan to tick off the list. The only day that lines up with our schedule is opening day. I can see some tickets on Ticketmaster Resale, Stubhub etc starting at $125 including fees. I totally understand there is a premium to be paid for opening day. What I would like to know is what the base price on average would be for an opening day ticket through Astros direct when they go on sale in March so I know whether we should jump on these or hold off. Ideally with our poor exchange rate, we would hope for something a bit cheaper but also don’t want to miss out on the experience.