I'm thinking if your terrestrial orchid was planted outdoors, it may have died from the cold, rather than the acid soil, Mother Raphaela. Most of them are a little bit tender for zone 4b, so unless some diligent gardener put a thick mulch over them, the cold probably got them.
Our soil here is slightly on the alkaline side, but where my Spathoglottis grow under my big oak trees it is more acid, so they don't seem to mind that. I know
@Ursula grows Bletillas in New Jersey, but her winters are not as cold as yours, and I don't know about the pH of her soil. Perhaps she will chime in here?
Just FYI, the Spathoglottis I have were mostly bought pretty reasonably at the local big box stores. I think the last ones I got were $10 for a gallon size pot in bloom, so they're not all that expensive. Now, if you were looking at buying Cypripediums, yes they are extremely expensive, but they also would probably be hardy to your area. ( maybe even grow wild near you!) I think they are native to much of the Northeast US and are also found in the Pacific Northwest.
Here are some pots of my Spaths from Lowe's:
