A great option if you want to spread the cost of National Trust Membership over 12 months. Excellent for budgeting. £5.75 to get the kids out into the fresh air and learn about history.
I've just joined the monthly scheme and have downloaded and printed a temporary members card ready to use at Fountains Abbey, North Yorkshire tomorrow.
By getting a National Trust for Scotland membership you can still visit all the National Trust places that you would if you bought from National Trust UK ( plus worldwide properties) see http://www.nts.org.uk/Site/Membership/Reciprocal-entry-sites/)
If you want to pay in a lump sum You can buy it as a one off Direct Debit for £65.25 though you might want to join the UK site because it has 3 months extra free at the moment for £72.75 (http://www.nationaltrust.org.uk/membership/) and there may be cashback offers