Yeah, Mark that's exactly what I did, bought two, and I did have to replace it at one year old, after the second time it got covered in sand I think I tried to use the pump to get the sand out instead of pulling up the pump and laboriously removing the sand with the
bucket. I was going to take the pump apart and clean it and see if I could get it running again, but... This second pump has been going strong for a year now too, and has survived one minor sand event no problem. Hopefully your sand is just in the soil and you will hit good rock for your water, but I think you can check well logs at the county to see average depths and strata info. Some counties may keep more detailed records than others, but most new
wells should be in the county records. Here the geology varies a lot and being on a steep hill some are deep and some are shallow. If you are able to do the lowering and lifting of the pump yourself, which at 70' would be pretty easy assuming you hang it on plastic pipe, then for the cost of one of these little pumps you can hardly go wrong.