Cloth!!! For a not-even-big outlay, you can just keep washing those feckers until DC is potty trained. The only ongoing "consumables" is the liners, which are (IIRC) £2.50 for 100 (ebay and mothercare).
You only need about 5-10 outers if you have a dryer. We didn't have a dryer, just dried on radiators: brilliant in winter when the heat is on, brilliant in summer when it's hot (the only less-than-efficient time was autumn and spring, when it would take a bit longer). But if you have a dryer, not applicable.
You would probably do a bit less than c.1 loada per day, but don't kid yourself: as new parents, even if you didn't use washable nappies, you'd get through a lot of laundry, what with all the baby clothing, your own clothing, towels, bibs, assorted stuff...
We ended up buying about 20 outers, but didn't need to: that's mainly because we liked all the colours (and a few patterned ones!). That said, ours were generally less than £2 each (ebay).
We used one "booster pad" during the day when DC was young, 2x at night. Later (like, in the last 4-6 months before potty-training), because DC had a larger bladder we needed to use 2x booster pads during the day as well.
Finally, we also used washable "wipes" (a big bundle of c.10x10" terry squares found in - believe it or not - the automotive aisle of Costco - something like 30 for £17. Not all the time - some travel packs of disposable wipes were employed.
Finally, (and foremost!) Congratulations!