PayPal Express Plugin Total Price error

I'm attempting to get the PayPal Express plugin to work with 2.2.

When transfer to paypal the price for each item in the basket it being rounded down and the decimal place moved e.g.

£14.99 goes to £1000
£45 goes to £5000

The code responsible is

Amount = new BasicAmountType()  // this is the per item cost
                    {
                        currencyID = PaypalHelper.GetPaypalCurrency(_currencyService.GetCurrencyById(_currencySettings.PrimaryStoreCurrencyId)),
                        Value = (item.ProductVariant.Price).ToString("N", new CultureInfo("en-us"))
                        
                    }  

Can anyone suggest how I can assign the correct figure to "Amount"

Darren Pegram

---Update---

Its actually nothing to do with rounding. We have all the product variants in the Db at price of £1000 but the tier pricing set to the correct amount for the product variant.

The issue now is how do I get the correct product variant tier price?