Try follwoing way:

**TestVendor/TestPayment/view/frontend/web/js/view/payment/method-renderer/testpayment-method.js**
<pre>
/*browser:true*/
/*global define*/
define(
    [
        'Magento_Checkout/js/view/payment/default',
        'Magento_Customer/js/customer-data',
        'Magento_Checkout/js/model/quote'
    ],
    function (Component, customerData, quote) {
        'use strict';

        return Component.extend({
            defaults: {
                template: 'TestVendor_TestPayment/payment/testpayment'
            },

            /** Returns send check to info */
            getMailingAddress: function() {
                return window.checkoutConfig.payment.checkmo.mailingAddress;
            },
            isDisplayed:function () {
                var customer = customerData.get('customer');
                console.log(customer().firstname);

                var totals = quote.getTotals()();
                var grand_total;
                if (totals) {
                    grand_total = totals.grand_total;
                } else {
                    grand_total = quote.grand_total;
                }

                console.log(grand_total);
                return true;
            }

        });
    }
);
</pre>
**TestVendor/TestPayment/view/frontend/web/template/payment/testpayment.html**
<pre>
&lt;div class="payment-method" data-bind="css: {'_active': (getCode() == isChecked())}">
    &lt;div class="payment-method-title field choice">
        &lt;input type="radio"
               name="payment[method]"
               class="radio"
               data-bind="attr: {'id': getCode()}, value: getCode(), checked: isChecked, click: selectPaymentMethod, visible: isRadioButtonVisible()"/>
        &lt;label data-bind="attr: {'for': getCode()}" class="label">&lt;span data-bind="text: getTitle()">&lt;/span>&lt;/label>
    &lt;/div>
    &lt;div class="payment-method-content">
        &lt;!-- ko foreach: getRegion('messages') -->
        &lt;!-- ko template: getTemplate() -->&lt;!-- /ko -->
        &lt;!--/ko-->
        &lt;div class="payment-method-billing-address">
            &lt;!-- ko foreach: $parent.getRegion(getBillingAddressFormName()) -->
            &lt;!-- ko template: getTemplate() -->&lt;!-- /ko -->
            &lt;!--/ko-->
        &lt;/div>
        &lt;div class="checkout-agreements-block">
            &lt;!-- ko foreach: $parent.getRegion('before-place-order') -->
            &lt;!-- ko template: getTemplate() -->&lt;!-- /ko -->
            &lt;!--/ko-->
        &lt;/div>
        &lt;div class="actions-toolbar">
            &lt;div class="primary">
                &lt;!-- ko if: isDisplayed() -->
                &lt;button class="action primary checkout"
                        type="submit"
                        data-bind="
                        click: placeOrder,
                        attr: {title: $t('Place Order')},
                        css: {disabled: !isPlaceOrderActionAllowed()},
                        enable: (getCode() == isChecked())
                        "
                        disabled>
                    &lt;span data-bind="i18n: 'Place Order'"></span>
                &lt;/button>
                &lt;!-- /ko -->
            &lt;/div>
        &lt;/div>
    &lt;/div>
&lt;/div>
</pre>

Run following command
<pre>
php bin/magento setup:static-content:deploy
</pre>

Clear cache.