Your wedding reception is likely to cost twice as much as you first imagined.
Every major expense always ends up costing more than we expect. This is because we all add things we'd not initially considered we wanted or were aware we needed. Most brides and grooms 'shop in increments' and can lose sight of the overall cost.
Elect a 'beady eyed bookkeeper' to keep a 'shopping list' with a running total of the costs as you add each new item to your list. Then you are both free to choose - either to increase your budget to fit your developing shopping list (your dream wedding, the ideal) or to reduce your shopping list to fit your budget (being practical, with realistic, affordable costs).
If you are able to take up the Special Wedding Package at the Castle, you can save some money on the wedding venue and wedding breakfast which you can then spend on other things. However the benefit of any saving could be lost if you allow yourself to get carried away with tempting extras!